1. Field of the Invention
The present invention relates to a method of creating an instant transfer that can be applied to a dark substrate. The transfer of the present invention is formed on an opaque substrate which is produced and a carrier film on which the transfer is positioned to adhere the transfer onto an article.
2. Background Art
Instant transfers have widely been utilized to facilitate rapid printing of images on a desired substrate. For example, instant transfers have been used to provide full color graphics which can then be transferred onto shirts, caps, jackets, mugs, plaques and other custom printed items in a matter of minutes. With the assistance of instant transfer printers, and computer technology, logos and photographs can readily be converted into instant transfers for application onto a variety of desired surfaces. While many different instant transfers have been developed, sublimation transfer is probably the most popular form of instant transfer used in today""s market.
Sublimation transfers create a color image on a fabric or hard surface by actually dyeing the fabric or surface. When a sublimation transfer is heat applied, the heat and pressure cause the sublimation dye to change from a solid directly into a gas and enter the substrate. While in its gaseous form, the sublimation dye actually enters the fibers of the desired garment or the coating of a non-porous object, thereby dyeing the item. Since the sublimation dye in this case actually penetrates either the fibers or the coating of the underlying substrate, the image created is essentially permanent and substantially non-destructible. Sublimation transfers also produce bright colors and are highly durable, as has been proven based on their ability to withstand repeated industrial laundering processes.
Within the category of sublimation transfers, there are several more specific sublimation sub-categories. Among these sub-categories, the two most commonly used are full color true sublimation and full color dye-sublimation. Between the two sublimation techniques, full color true sublimation produces the most vibrant colors. A true sublimation ribbon contains dyes for three colors-cyan, magenta and yellow, which are used to create all of the colors of the transfer. The correct amount of each color is then thermally applied from the sublimation ribbon to the backing material, and the transfer emerges from the printer as one multi-color graphic, ready for application. In contrast, with full color dye-sublimation, the dye is sublimated onto a transfer paper, after which the dye migrates to the substrate during application. Such applications are highly beneficial for non-porous, hard objects, such as mugs and trophies, due to the high pressure required for application. With applications on soft items, such as shirts and caps, a transfer using full color dye-sublimation usually results in faded colors. Dye sublimated images, especially photographs, are particularly sharp versus their counterpart true sublimation image.
With dye sublimation, the ribbon actually sublimates the carrier sheet as it runs through the printer and the ultimate graphic must then be re-sublimated on the final substrate. This is, accordingly, considered a second-generation sublimation process. True sublimation uses a combination of heat and pressure from the thermal printing head, by which the dye has been transferred to a special carrier sheet. With the use of this special carrier sheet, the sublimation particles do not sublimate during printing. When heat is applied to transfer the image onto an item, the dye on the carrier sheet sublimates to the substrate. This is considered a first generation sublimation process.
While sublimation transfers produce brighter colors and constitute a substantially permanent and indestructible transfer, sublimation processes offer the best results on white or light-color fabrics with a high polyester content. Other final substrates, such as ceramics, glass, metals and plastics which are pre-treated with a polymer coating, also constitute good final substrates for sublimation transfers.
Notwithstanding the advantages of sublimation transfers, there exist several limitations. Sublimation transfers cannot be applied to such final substrates as 50xe2x80x9450 polyester cotton blends or non-polyester fabrics, but rather the non-polyester fabric must be sprayed or soaked with a special polyester-based prepping liquid to facilitate sublimation transfer. Sublimation transfers applied on a 100% cotton final substrate may result in a sublimation image lacking vibrant colors. With porous substrates, the colors of the sublimated image may not appear as vibrant as desired. In addition, sublimation transfers are not detectable on dark surfaces. Since it is impossible to create a white sublimation dye, and since other sublimation dyes are absorbed into the dark background, it is impossible to see a sublimated image on a dark final substrate. There has thus been no efficient, durable and effective process for creating an instant transfer on a dark surface. Accordingly, there is a need for a method of creating an instant transfer on porous final substrates, wherein the resultant transfer is vibrant, durable and can be efficiently produced.
There exists yet another kind of instant transfer, referred to as a xe2x80x9cwaxxe2x80x9d transfer. With this transfer technique, the color image is printed onto a polymer coated paper. With the use of a high temperature application process, the polymer coating xe2x80x9cmeltsxe2x80x9d onto the substrate. However, with such wax transfers, the polymer coating creates a non-desirable polymer border around the polymer transfer which has a different appearance and texture than the desired transfer. Accordingly, such wax transfer technology is generally undesirable.
With the above-identified instant transfer technologies, the transfers are created on a carrier medium, which is in turn utilized to re-transfer that carrier medium to a final substrate. For example, with the sublimation transfer process, the desired image is transferred onto a carrier medium such as paper, which is then in turn heat applied to a final substrate. As a result, with a sublimation transfer or a wax transfer, there is often a color shift which occurs following the dual transfers that are required to create a transfer on the final substrate. To remedy such color shifting problems, computer technology is often utilized to pre-shift the color changes so that the resulting transfer creates the desired image. However, slight changes in the surface characteristics of the final substrate or the process parameters alters the resulting color which makes it impossible to accurately pre-shift. Such problems associated with color shifting create additional software and programming issues which effect predictability and reproduceability of the process.
As a result, there is a need for a transfer process which can be utilized with a variety of final substrates, including porous and non-porous materials, as well as dark colored substrates. Moreover, there is a need for an efficient transfer process which creates a transfer without the associative color shifting problems and durability concerns.
It is an object of the present invention to provide a method of creating a transfer. The method comprises providing a heat sensitive polymer substrate having a heat sensitive opaque polymer film with top and bottom surfaces and a heat activated adhesive disposed upon one surface of the heat sensitive opaque polymer film. The method further includes providing a second carrier film including a second polymer film with first and second opposite surfaces and a second adhesive having a peel strength which decreases with increasing temperature. The second adhesive is disposed on the first surface of the second film. The method further includes printing resin solids in a desired graphic onto the top surface of the opaque polymer film. The printing is at a temperature which is below the temperature at which the polymer substrate is activated and such that printing causes the resin solids to penetrate into the opaque polymer film to create a durable printed transfer. The method further includes positioning the printed transfer on the first surface of the second film and adhering the printed surface onto a thermally adherable article on which the graphic is to appear. This is accomplished by applying sufficient heat to the polymer substrate at a temperature which is above the temperature which the polymer substrate activates so as to activate the polymer substrate and bond the polymer substrate to the article. The heat is also at a temperature at which substantially reduces the peel strength of the second adhesive.
Another embodiment of the present invention is to provide a method of creating a transfer. The method comprises providing a heat sensitive polymer substrate having a heat sensitive opaque polymer film having top and bottom surfaces, a heat activated adhesive disposed upon one surface of the heat sensitive opaque polymer film, and a releasably coated carrier film which releasably carries the heat sensitive opaque polymer film with the heat activated adhesive disposed between the heat sensitive opaque polymer film and the releasably coated carrier film. The method further comprises providing a second carrier film including a second polymer film having first and second opposite surfaces and a second adhesive having a peel strength which decreases with increasing temperature. The second adhesive is disposed on the first surface of the second film. The method further comprises printing resin solids in a desired graphic onto the top surface of the opaque polymer film. The printing is at a temperature which is below the temperature at which the polymer substrate is activated and such that printing causes the resin solids to penetrate into the opaque polymer film to create a durable printed transfer. The method further comprises positioning the printed transfer on the first surface of the second film and adhering the printed transfer onto a thermally adherable article on which the graphic is to appear by applying sufficient heat to the polymer substrate at a temperature which is above the temperature which the polymer substrate activates so as to activate the polymer substrate and bond the polymer substrate to the article and at which to substantially reduce the peel strength of the second adhesive, and by applying sufficient force to adhere the graphic to the article.